Whitman is a descendant of two New Jersey political families, the Todds and the Schleys, and is related by marriage to New York's politically prestigious Whitman family. Her husband, who died in July 2015, was private equity investor John R. Whitman, a grandson of early 20th-century Governor of New YorkCharles S. Whitman. Her maternal grandfather, Reeve Schley, was a member of Wolf's Head Society at Yale and the vice president of Chase Bank. He was also a longtime president of the Russian-American Chamber of Commerce.

In 1990, Whitman ran for the U.S. Senate against incumbent Bill Bradley, and lost in a close election.[11] She was considered as an underdog against the popular Bradley. During her campaign, Whitman criticized the income tax hike proposed by then governor James Florio. Bradley did not take a stance on the issue.

In 1993, Whitman helped to found the Committee for Responsible Government, an advocacy group espousing moderate positions in the Republican Party. In 1997, the CRG softened its pro-choice position, and renamed itself as the Republican Leadership Council.

Whitman ran against incumbent James Florio for governor in 1993, and defeated him by one percentage point to become the first female governor in New Jersey history. She was the second woman and first Republican woman to defeat an incumbent governor in a general election, but was unable to gain a majority of the votes, winning by a plurality. Charges of suppression of minority votes were raised during the campaign.[12]

Whitman pledged during the campaign that she would lower state taxes by 10% a year for three years. Once in office, she kept the campaign promise, and lowered income taxes.[13] The decline in the tax burden made it likely that the issue of tax revenue shortfall would be addressed later. Jim Saxton, in a report to the federal congress, argued that New Jersey's income tax cuts improved "the well-being of the New Jersey family", and would not lead to an increase in property taxes.[14] Saxton cited Tim Goodspeed's research and a recent paper published by the Manhattan Institute. He admitted that "a few localities raised [property] taxes," as expected by Goodspeed, but both Saxton and Goodspeed counted on the flypaper effect to mitigate any broad or persistent increases. However, the resulting long-term deficit could not be easily reversed, and subsequent governors ran into difficulties with the cumulative revenue losses and interest payments on the debt the state government issued.

In 1995, Whitman was criticized for saying that young African-American males sometimes played a game known as jewels in the crown, which she claimed had as its intent having as many children as possible out of wedlock. Whitman subsequently apologized, and voiced her opposition to attempts by Congressional Republicans to bar unwed teenage mothers from receiving welfare payments.[15]

Also in 1995, Whitman became the first woman to deliver a State of the Union response by herself; this was also the first State of the Union response given to a live audience.[16]

In 1996, Whitman joined a New Jersey State Police patrol in Camden, New Jersey. During the patrol, the officers stopped a 16-year-old African American male named Sherron Rolax, and frisked him. The police found nothing on him, but Whitman frisked the youth herself, too, while a state trooper photographed the act. In 2000, the image of the smiling governor frisking Rolax was published in newspapers statewide, which drew criticism from civil rights leaders who saw the incident as violation of Rolax's civil rights and Whitman's endorsement of racial profiling – especially since Rolax was not arrested or found to be violating any law. Whitman later told the press that she regretted the incident, and pointed to her efforts in 1999 against the New Jersey State Police force's racial profiling practices. In 2001, Rolax learned about the photograph, and sued Whitman in federal court, claiming that the search was illegal and constituted an invasion of privacy. The appeals court agreed that the act did suggest "an intentional violation" of Rolax's rights, and that he "was detained and used for political purposes by his governor," but upheld the trial court's decision that it was too late to sue.[17][18]

In 1996, Whitman rejected the Advisory Council's recommendation to spend tax money on a needle exchange to reduce incidence of HIV infections.[19]

Whitman was re-elected in 1997, narrowly defeating Jim McGreevey, the mayor of Woodbridge Township, who criticized Whitman's record on property taxes and automobile insurance rates. McGreevey also criticized Whitman for allowing a private sector company to administer the vehicle inspection program. In the 1997 election, the early prediction was that Whitman, as an incumbent, would have an easy win. The result, however, was that Whitman duplicated her 1993 election with only a one-point victory and a plurality of the votes. Murray Sabrin, a college professor who ran as a Libertarian candidate, and finished third with five percent of the vote, received votes mostly from conservative Republicans who might otherwise have voted for Whitman.

In 1997, she repealed the one percentage-point increase to the state sales tax that her predecessor Governor Florio had imposed, reducing the rate from 7% to 6%, instituted education reforms, and removed excise taxes on professional wrestling, which led the World Wrestling Federation to resume events in New Jersey. In 1999, Whitman vetoed a bill that outlawed partial birth abortion. The veto was overridden, but the statute was subsequently declared unconstitutional by the judiciary. In 1999, she made a cameo appearance on the television show Law & Order: Special Victims Unit.[20]

In 1999, Whitman fired Colonel Carl A. Williams, head of the New Jersey State Police, after he was quoted as saying that cocaine and marijuana traffickers were often members of minority groups, while the methamphetamine trade was controlled primarily by white biker gangs.[21]

In 2000, under Whitman's leadership, New Jersey's violation of the federal one-hour air quality standard for ground level ozone dropped to 4 from 45 in 1988. Beach closings reached a record low, and the Natural Resources Defense Council recognized New Jersey for instituting the most comprehensive beach monitoring system in the country. New Jersey implemented a new watershed management program, and became a national leader in opening shellfish beds for harvesting. Whitman agreed to give tax money to owners of one million acres (4,000 km²) or more of open space and farmland in New Jersey.

When Democratic Senator Frank Lautenberg announced that he would not seek re-election in 2000, Whitman considered running,[22] but ultimately decided not to.

In the final weeks of the Clinton administration in January 2001, the administration ratified a new drinking water standard of 0.01 mg/L (10 parts per billion, or ppb) arsenic to take effect in January 2006. The old drinking water standard of 0.05 mg/L (equal to 50 ppb) arsenic had been in effect since 1942, and the EPA, since the late 1980s, had weighed the pros and cons of lowering the maximum contaminant level (MCL) of arsenic.[25] The incoming Bush administration suspended the midnight regulation, but after months of research, the EPA approved the new 10 ppb arsenic standard to take effect in January 2006 as initially planned.[26]

In 2001, the EPA produced a report detailing the expected effects of global warming in each state in the country. President Bush dismissed the report as the work of "the bureaucracy."[27]

Whitman appeared twice in New York City after the September 11 attacks to inform New Yorkers that the toxins released by the attacks posed no threat to their health.[28] On September 18, the EPA released a report in which Whitman said, "Given the scope of the tragedy from last week, I am glad to reassure the people of New York and Washington, D.C. that their air is safe to breathe and their water is safe to drink." She also said, "The concentrations are such that they don't pose a health hazard...We're going to make sure everybody is safe."[29] A 2003 report by the EPA inspector general determined that the assurance was misleading, because the EPA "did not have sufficient data and analyses" to justify it.[30]

A report in July 2003 by the EPA Office of Solid Waste and Emergency Response gave extensive documentation supporting many of the inspector general's conclusions.[31] The report further found that the White House had "convinced EPA to add reassuring statements and delete cautionary ones" by having the National Security Council control EPA communications after the September 11 attacks.[32] In December 2007, legal proceedings began on the responsibility of government officials in the aftermath of the September 11, 2001 attacks. Whitman was among the defendants. The plaintiffs alleged that Whitman was at fault for saying that the downtown New York air was safe in the aftermath of the attacks.[33] In April 2008, the United States Court of Appeals for the Second Circuit overruled the district court, holding that as EPA administrator, Whitman could not be held liable for assuring the World Trade Center area residents that the air was safe for breathing after the buildings collapsed. The court ruled that Whitman had based her statement on contradictory information from President Bush. The U.S. Department of Justice had argued that holding the agency liable would establish a risky legal precedent because such holding would make public officials afraid of making public statements.

On June 27, 2003, after having several public conflicts with the Bush administration, Whitman resigned.[34][35]

In an interview in 2007, Whitman stated that Vice President Dick Cheney's insistence on easing air pollution controls, not the personal reasons she cited at the time, led to her resignation.[36] At the time, Cheney pushed the EPA to institute a new rule allowing power plants to make major alterations without installing costly new pollution controls.[36] Whitman stepped down in protest against such demand by the White House, she said.[36] She decided that because she did not agree with the rule, she would not be able to defend it if it were to be challenged in a legal action.[36] The federal court eventually overturned the rule on the ground that it violated the Clean Air Act.[36]

In 2016, Whitman apologized for the first time for her declaration a week after 9/11 that the air in lower Manhattan was safe to breathe. [37]

In early 2005, Whitman released a book entitled It's My Party, Too: Taking Back the Republican Party... And Bringing the Country Together Again in which she criticizes the policies of the George W. Bush administration and its electoral strategy, which she views as divisive.

The defining feature of the conservative viewpoint is a faith in the ability, and a respect for the right, of individuals to make their own decisions – economic, social, and spiritual – about their lives. The true conservative understands that government's track record in respecting individual rights is poor when it dictates individual choices.[39]

The last chapter of that book, entitled "A Time for Radical Moderates", speaks to radical centrists across the political spectrum.[40]

In December 2010, Whitman criticized the 2008 Republican vice president candidate Sarah Palin, commenting that if Palin were to run for President in 2012 and win the Republican nomination, "I don't think she'll win nationwide... [she will] energize the base. But the base isn't big enough and Republicans should have learned that." She went on to say that if Palin were to run,

She'd have to show me a lot more than I've seen thus far, as far as an understanding of the depth and the complexity of the issues that we face... she was a governor, but the fact that she left office before even completing her first term, it's just not an attitude that I think is necessarily in the best interest of your constituents, rather what's in your own best interest.[41]

^Cohen, Joyce. "HAVENS; Weekender | Tewksbury, N.J.", The New York Times, November 22, 2002. Retrieved March 14, 2011. "The most famous resident is New Jersey's former governor Christine Todd Whitman, now administrator of the Environmental Protection Agency, whose family owns a farm there."